1) Field of the Disclosure
The disclosure relates generally to panel and access door assemblies for attachment to structures, and more particularly, to panel and access door assemblies having unique edgebands for attachment to structural frames of vehicles, such as aircraft, and other structures.
2) Description of Related Art
In many applications, panels and access doors may be assembled by mechanically fastening the panels together and portions of the access doors together with one or more rows of fasteners, such as rivets, bolts, screws, or other fasteners, by chemically bonding the panels together and portions of the access doors with an adhesive or another chemical bonding element, or by another means of joining or fastening known in the art. Such panel assemblies and/or access door assemblies may be attached to structural frames or other structures or parts of various transport vehicles, such as aircraft, spacecraft, rotorcraft, watercraft, automobiles, trucks, buses, or other transport vehicles, or of architectural structures such as buildings, bridges, or other structures.
In particular, an aircraft fuselage or body may be manufactured with multiple skin panels mechanically fastened together both circumferentially and longitudinally with rows of fasteners such as metal rivets. Such skin panels may be used to form fairings which are structures to reduce drag and to produce a smooth outline and appearance of the aircraft. Fairings, such as wing-to-body fairings, provide an aerodynamic shell between the wing and the fuselage or body of an aircraft to form the outer skin of the aircraft. Known wing-to-body fairing panel assemblies typically have panels with a linear or straight edge between two adjacent panels attached to an aircraft structural frame.
Illustrations of known wing-to-body fairing panel assemblies are shown in FIGS. 2A-2C and FIGS. 3-4. FIG. 2A is an illustration of an interior side perspective view of a known aircraft wing-to-body fairing panel assembly 30 formed of panel elements 32a, 32b having linear or straight edges 34a, 34b (see also FIG. 2C), respectively. As shown in FIGS. 2A-2C, the panel elements 32a, 32b may have, respectively, sides 36a, 36b that may or may not be attached to further panel elements; edgebands 38a, 38b having an edgeband width 54 (see FIG. 2B) and each edgeband 38a, 38b having one or more rows of panel openings 44a, 44b (see FIG. 2B); honeycomb core portions 40a, 40b with ramped portions 41a, 41b (see FIG. 2A); interior surfaces 50a, 50b (see FIG. 2A); and, exterior surfaces 52a, 52b (see FIG. 2C). The panel elements 32a, 32b may typically be made of composite material and/or metal material, and the edgebands 38a, 38b, although thinner in width than the honeycomb core portions 40a, 40b, typically weigh more than the honeycomb core portions 40a, 40b due to the use of lighter weight material in the honeycomb core portions 40a, 40b and the use of heavier weight material in the edgebands 38a, 38b. 
FIG. 2B is an illustration of an interior front perspective view of the known aircraft wing-to-body fairing panel assembly 30 of FIG. 2A. FIG. 2C is an illustration of an exterior perspective view of the known aircraft wing-to-body fairing panel assembly 30 of FIG. 2A. As shown in FIG. 2B, the panel elements 32a, 32b may be joined to first end edges 42a, 42b, having a J-profile 48, of an aircraft structural frame element 46 via frame openings 58a, 58b that correspond to the panel openings 44a, 44b of the panel elements 32a, 32b. The panel elements 32a, 32b are joined to the aircraft structural frame element 46 and, in turn, to each other, via fasteners 56 (see FIGS. 2C, 3) inserted through the panel openings 44a, 44b and corresponding frame openings 58a, 58b. 
FIG. 3 is an illustration of a close-up perspective view of an exterior portion of the panel element 32a of the known aircraft wing-to-body fairing panel assembly 30 of FIG. 2A joined to the aircraft structural frame element 46. As shown in FIG. 3, the aircraft structural frame element 46 further has a second end edge 60 and a body 62 with openings 64.
FIG. 4 is an illustration of an interior perspective view of an interface 66 between the two adjacent panel elements 32a, 32b of the known aircraft wing-to-body fairing panel assembly 30 of FIG. 2A. The interface 66 is formed between the linear or straight edges 34a, 34b. The edgeband width 54 is formed between an end 68 of the edgeband 38a and an end 70 of the edgeband 38b. 
The use of a double row of fasteners or multiple rows of fasteners in the edgeband width of such known panel assemblies as shown in FIGS. 2A-2C and FIGS. 3-4 may increase the edgeband width, and, in turn, may increase the amount of heavier material that may be used in the edgebands. This may result in an increase in the overall weight of the panel assemblies and the structure to which it is attached. Moreover, the use of a double row of fasteners or multiple rows of fasteners in the edgeband width may increase the number of fasteners needed to assemble the panel assemblies. This may further result in an increase in the overall weight of the panel assemblies and the structure to which it is attached. Finally, with the use of an increased number of fasteners, the cost of manufacturing the panel assemblies may increase due to increased time and labor that may be required to install the fasteners.
Illustrations of removable, non-hinged, known access door assemblies are shown in FIGS. 15A-15D. FIG. 15A is an illustration of an exterior perspective view of a known access door assembly 300. FIG. 15B is an illustration of an exterior perspective view of the known access door assembly 300 of FIG. 15A with an access door 302 removed. FIG. 15C is an illustration of an interior perspective view of the known access door assembly 300 of FIG. 15A. FIG. 15D is an illustration of an interior perspective view of the known access door assembly 300 of FIG. 15A with the access door 302 removed.
As shown in FIG. 15A, the known access door assembly 300 has an access door 302 with a circular edge 303 (alternatively, the edge may be linear), an exterior side 304, an interior side 306 (see FIG. 15C), and a plurality of access door openings 308. As further shown in FIG. 15A, the known access door assembly 300 has a support portion 310 adjacent the access door 302 having an exterior side 312, an interior side 314 (see FIG. 15C), and a plurality of support portion openings 316.
As shown in FIG. 15B, the known access door assembly 300 further has a doubler 318 attached to the support portion 310 and has an exterior side 320, an interior side 322 (see FIG. 15D), and a double row plurality of doubler openings 324a, 324b (see FIG. 15D). The access door 302 is designed to fit against a recessed edge portion 326 over the doubler 318 and flush with the exterior side 312 of the support portion 310.
As shown in FIG. 3A, the known access door assembly 300 is joined to a structure 328, such as an aircraft structural element 330, having an exterior side 332 and an interior side 334 (see FIG. 15D). FIG. 15B shows a diameter (d1) 338 of the interior opening 336, and FIG. 15D shows a diameter (d2) 340 of the doubler 318. The access door 302 may be joined to the doubler 318, and in turn, to the structure 328 via fastener elements 342 (see FIG. 15A) inserted through the access door openings 308 and the corresponding doubler openings 324a (see FIG. 15B). The structure portion 310 may be attached to the doubler 318 via fastener elements 342 (see FIG. 15A) inserted through the support portion openings 316 and the corresponding doubler openings 324b (see FIG. 15D). This results in a double row of fastener elements 342 on each side of the interface of the circular edge 303 of the access door 302 (see FIG. 15A).
The use of a double row of fastener elements or multiple rows of fastener elements in the known access door assemblies, such as known access door assembly 300, shown in FIGS. 15A-15D, may increase the diameter (d2) 340 of the interior of the doubler 318 and, in turn, may increase the amount of doubler material used in the known access door assembly 300. This may result in an increase in the overall weight of such known access door assembly 300 and the structure 328 to which it is attached. Moreover, the use of a double row of fastener elements or multiple rows of fastener elements on each side of the interface of the circular edge 303 of the access door 302 may increase the number of fastener elements needed to assemble the known access door assembly 300. This may further result in an increase in the overall weight of the known access door assembly 300 and the structure 328 to which it is attached. Finally, with the use of an increased number of fastener elements, the cost of manufacturing such known access door assemblies may increase due to increased time and labor that may be required to install the fastener elements.
Accordingly, there is a need in the art for an improved panel assembly and method of making the same that provide advantages over known assemblies and methods. Further, there is a need in the art for an improved access door assembly and method of making the same that provide advantages over known assemblies and methods.